Instructions for Types DB-75, DB-100 and DBF-40
W1001317Instructions for Types DB-75, DB-100 and DBF-40 Air Circuit Breakers
600 volts A-C 250 Volts D-C
Continuous Current Rating
DB-75
DB-100
2,000 Amperes 2,500 Amperes, 3,000 Amperes
4,000 Amperes 5,000 Amperes / D-C 6,000 Amperes{Only
Westinghouse Electric Corporation
- - - Switchgear Division, East
I. B. 33 850-4 & 5D, Effective
Pittsburgh, Pa. November, 1966.
Supersedes
I.
B.
33
850
4
&
5C,
May,
1962.
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TABLE OF CONTENTS
Part One
RECEIVING, HANDLING AND STORING
Inspection
Storing...
Page 7
7 7
Past Two
. Connections
Enclosures.
INSTALLATION
- Pages 8 11
8 8
Part Three
MAINTENANCE
- Pages 12 24
Pole Unit
14
Contacts Maintenance of Contacts
.
14 14
.i<
Operating Mechanism
14
k
Closing Solenoid.
Overcurrent Tripping Device
17 18
-i . -
. Description
18
Construction
18
Installation and Removal
18
f
Adjustment of Trip Screw
19
Operation
20
Standard Overcurrent Tripping Device
20
Selective Overcurrent Tripping Device
21
-Instantaneous Overcurrent Tripping Device (Single Element)
Time Current Characteristics
22 22
^ Calibration
Maintenance X
23 23
Control Relay
24
Inspection
24
Maintenance
24
Shunt Trip Attachment
24
Inspection
24
Maintenance
24
Undervoltage Trip Attachment
24
Undervoltage Time Delay Attachment
26
Inspection
Maintenance. . .
26
..
26
Auxiliary Switch
26
Inspection
26
Maintenance
26
)
(
2
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TABLE
Part Three
MAINTENANCE (Continued)
- Pages 24 30
Alarm Switch Attachment.
26
Inspection
26
Maintenance
29
Electric Lockout Attachment
.
29
Inspection
29
Maintenance
29
Key Lock Attachment
,
29
Inspection
29
Maintenance
30
Key Interlock Attachment
30
Inspection
30
Maintenance
- - Rectifier Unit for A C Undervoltage and A C Electric Lockout Attachments
. Inspection
30 30 30
Maintenance
30
Reverse Current Trip Attachment
30
Inspection
30
Maintenance
31
· S'
Field Discharge Switch
33
V v.
Recommended Spare Parts
34
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3
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LIST OF ILLUSTRATIONS
c
Figure
Page
- 1 DB 75 Outline and Mounting Dimensions
9
- 1A DB 100 Outline and Mounting Dimensions
10
IB DBF-40 Outline and Mounting Dimensions
11
- 1C DB 75 Outline and Mounting Dimensions
12
2 Typical Wiring Diagrams
13
- - - 3 Cross Sectional View of DB 75 and DB 100 Circuit Breakers
15
- - 3A DB 75 and DB 100 Three Position Operating Mechanism
16
- - - 4 Adjusting Limits of Main and Arcing Contacts for DB 75 and DB 100 Cir
-- cuit Breakers
. 5 Closing Solenoid Construction Details
17 18
6 Cross-Sectional View of Overqurrent Tripping Device with Long Delay and
- - Instantaneous Elements .
19
7 Schematic and Typical Time Current Characteristics of Overcurrent Trip
ping Device with Long Delay and Instantaneous Elements
20
- 8 Cross Sectional View of Overcurrent Tripping Device with Long Delay and
Short Delay Elements
21
8A Selective Overcurrent Trip Operations
22
. /<
- 9 Schematic and Typical Time-Current Characteristics of Overcurrent Trip
·/ -
ping Device with Long Delay and Short Delay Elements
23
10A Schematic Diagram of Overcurrent Tripping Device with Instantaneous
Element Only
24
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- 10B Typical Time Current Characteristics of Overcurrent Tripping Device with
;i
1
11 12 13 14 15 16 17 18 19 20
Instantaneous Element Only Control Relay Construction Details
24
.'
25
-- -- . Shunt Trip Attachment Construction Details
Undervditage Trip Attachment Construction Details
26 27
-- Undervoltdge Time Attachment Construction Details
28
-- Auxiliary Switch Construction Details
28
-- Alarm Switch Attachment Construction Details
29
-- Electrical Lockout Attachment Construction Details
29
- -- -- . . Key Lock or Key Interlock Attachment Construction Details
30
Rectifier Unit for A C Undervoltage and Electrical Lockout Attachments . . 31
- - Reverse Current Trip Attachment Types "DB 75" and "DB 100" Air
-- Circuit Breakers
32
- 21 Cross Section View of Field Discharge Pole Unit
33
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. - - LB 33 850 4 & 5D
"DB" AIR CIRCUIT BREAKERS
WESTINGHOUSE
TYPE w " AIR CIRCUIT BREAKERS
Type "DB" air circuit breaker is designed to give continuous and reliable
- service as the protective link between the power source and associated pro
- ductive equipment. This breaker is built to operate with a minimum of main
. tenance, while at the same time its simplified construction permits maximum
accessibility for inspection and adjustment when required The ease with which
attachments may be added or removed is an outstanding feature of the "DB"
. design
- For the greatest measure of safety to operating personnel and also to min
/·/
imize maintenance requirements, the breaker should be mounted in an enclosure
. suitable to local operating conditions. A selection of standard enclosures is
available for various applications
Important: To assure proper functioning, inspect each breaker at reg
-. ulai intervals in accordance with a systematic maintenance schedule ^The frequency and character of the inspections will for the most part
. be determined by the severity of the duty performed The minimum
- . - requirements, however, should consist of a light monthly inspection,
with a thorough inspection semi annually Occasional checks on cali
. bration as well as on coordination and freedom of all moving parts,
must be included in the maintenance schedule Consult Westinghouse engineering and service personnel for recommendations pertaining to
special operating or maintenance conditions.
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PART ONE
. . - - I B 33 850 4 & 5D
"DB" AIR CIRCUIT BREAKERS
RECEIVING, HANDLING AND STORING
I
- - - . TYPES "DB 75" AND "DB 100" AIR CIR
a. Observe whether all parts are in proper
CUIT BREAKERS are shipped in wooden crates alignment and move freely
with all attachments mounted in place.
- Important: To avoid damage to the break
ers, do not use hooks in handling.
b. Be sure that the contacts are clean and properly aligned. The center finger of the stationary
. arcing contacts should have a slight lead
.C The hinge end of the moving contact is
lubricated with graphite grease and is therefore
Table No. 1
NET WEIGHTS OF 3 POLE BREAKER
DB 75
--DB 100
DBF-40
. 475 lbs (Add 50 lbs for D O.)
. . 525
550
lbs lbs
(Add (Add
75 75
lbs lbs
for for
DD.OO.))
. Immediately upon receipt, examine shipment for
any loss or damage incurred during shipment If
injury or rough handling is evident, file a damage
. claim at once with the transportation company and
notify the nearest Westinghouse Sales Office
, When unpacking be sure that no loose parts . are missing or left in the packing material Report
all shortages at once. Blow out any dust or particles
of packing the circuit
bmreaatekreiarlptahratts.may
have
accumulated
on
. black. For a description of contact alignment refer
to "CONTACTS", Page 14
4. If the contacts are in alignment and all parts
move freely, continue the closing until the breaker
. is latched
. . 5 Hold the maintenance operating handle down
. Push the "Push to Trip" button to trip breaker
a. The toggle linkage should collapse and the
. moving contact assembly move freely to the full
open position This should be followed by complete resetting of the links in the toggle mechanism as
. the handle is raised
- b. The links must always be free to move with
. out friction or binding
- 6» Check the attachments for operation in accord
. ance with the appropriate instructions as given
under "Maintenance", Part III of this book
INSPECTION
- - The "DB" breaker assembly consists of a co or - - dinated group of ub assemblies mounted on a sup
. ^ ^ ibpnoesrpmtienocgutinoptnaesndefwol ritThphrteohpecoeprmaonppeleeltrieantbiaorevnaeksrhteiorcuaallsdsp,eomtshibteiloryenf.iosArtelo,l
. - be made with the breaker in this position Final in
- spection should preferably be made with the break
. er in its permanent mounting
Inspect the breaker as follows:
. . 1 Lift trip finger by hand to make sure that it
does not bind
.2 Remove any foreign particles from the hinge
end of the moving contacts.
.3 Insert the maintenance operating handle and
. slowly close the breaker
Note: It is not advisable to lubricate any parts o£ the breaker. The lubrication supplied during factory assembly is sufficient for years
of service. The lubricant is of a special form which is used sparingly. The addition of oil
will only promote the accumulation of dust and dirt.
STORING
- If circuit breakers are not to be installed in their
permanent locations at once, they should be care
fully inspected for loose or damaged parts and then
. stored in a clean, dry place in an upright position
to avoid damage to the circuit breaker parts A covering of paper will prevent dust from settling on
. the circuit breaker parts and is preferred to packing
or other materials which are apt to absorb moisture
FOR SAFETY REASONS, STORE THE BREAKER IN
THE OPEN POSITION,
7
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1.
PART TWO
INSTALLATION
r
Type "DB" circuit breakers are furnished as
- complete unit assemblies and the installation con
- sists of: (1) bolting them to the supporting frame
- work or structure; (2) connecting the current carry
. ing cables or bus bars; and (3) completing any
secondary control wiring that may be necessary Caution: During installation, the circuit
. breaker should be in the open position Be
- sure to de energize the load and control leads
to be connected, and also the section of the
. switchboard where installation is being made
-. . Mounting dimensions and details of the front en
closure cutouts are shown in Figs 1, 1A, IB, and 1C
CONNECTIONS
. Typical circuit breaker wiring diagrams are
shown in Fig should have
2, The connecting cables or bus bars
adequate current carrying capacity,
. or heat will be conducted to the circuit breaker
resulting in possible excessive temperature rise
Connecting cables or bus bars must be supported
. so that the circuit breaker studs will not be subjected
to unnecessary stresses
ENCLOSURES
-)
To prevent distortion of the breaker panel, the
- supporting structure should be checked for align . ment Magnetic material in the mounting structure . should have at least two inches clearance to the
breaker studs
- - . A manual closing handle is supplied with each
order of DB 75 and DB 100 breakers This handle is for maintenance only and in no case should it be
. used for closing the breaker when primary circuit
is energized
The breaker is normally mounted in the enclosure
. - along with accompanying bus work terminating in
cable clamps Where covers are mounted on en
closures, theyare to be removedanddrilled to provide
for connecting cable, All connections should be
clean, smooth and free from burrs to assume full
. contact area They should be firmly clamped or
. bolted in place to prevent excessive heating Cable
. must be adequately braced to withstand full short
circuit currents
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INSTALLATION
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"DB" AIR CIRCUIT BREAKERS
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. . - FIG 1 Type DB 100 Air Circuit Breaker, Outline and Mounting Dimensions
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. INSTALLATION
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. - FIG IB, Type DBF 40 Fixed Outline and Mounting Dimensions
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. . FIG 2 Typical Wiring Diagrams
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PART THREE
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MAINTENANCE
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POLE UNIT
. Each, pole unit (Fig 3) is mounted on a separate . molded base The molded bases are attached to the
- mounting panel and provide insulation for the break
. er studs
moTldheedubpapseerbsytutdwoanbdolctso.nTtahcet
are attached to the moving contact arm
is pivoted on the lower stud and is attached to the
. cross bar through an insulating link The lower stud
. is fastened to the molded base by four bolts
. . Contacts. (See Fig 3 ) The arcing contacts must
. touch first on closing and open last on opening
- Do not adjust one set of contacts without check . ing the complete sequence of all poles With the
breaker open proceed in the following order:
.1
. vary
Turn adjusting nuts (A) on insulating main contact pressure Use ,00S feeler
link to
gauge,
. 1/4 inch wide by 6 inches long, inserted as shown
in Fig, 4A to check clearance
Feeler (X) above contact fingers insures that they
. have all been deflected Feeler (Y) inserted below . fingers insures that they have not gone solid
. - 2 With breaker closed and latched, apply pres
. ^ sure
Fig
on 4B,
each stationaryV
When spring is
rcing contact, part "a" of fully compressed or solid,
. Maintenance of Contacts. Rough or high
spots should be removed with a file or sandpaper When dressing contacts be sure to protect the
. hinged contact of all poles with a cloth to prevent
foreign matter from lodging in the hinged contact
. Cautions All power must be removed when
replacing, maintaining or adjusting contacts
OPERATING MECHANISM
. - - - The operating mechanism (Figs 3 3A) is non ad
- justable and consists of a series of non ferrous links
. designed to secure low closing and trippng forces
To check for friction, with the breaker open, raise
. trip finger and slowly lower the closing handle . Release trip finger and slowly raise handle The
linkage should follow the handle without sticking
. and a "click" will be heard just before the handle
reaches the full up position
.To remove the mechanism proceed as follows:
1 Remove the breaker cross bar,
.2 Loosen the outboard bearings at the ends of
. the trip bar
- a. In reassembly, tighten bolts holding out
. board bearings only when bearings have been
adjusted to prevent any binding of trip shaft
. - 3 Remove the tension rods between the mech
anism and aluminum panel.
. 4. Free the pin (1-3) * from the moving core To
clearance from moving arcing contact (b) should
. ' be /32 to
-- - insulating
Vs inch Adjust link however,
by turning nuts (A) on clearances of main con
tacts as described in part (1) must be maintained,
. free the pin, first remove the cotter phi from the
spacer on the right side of the pin Partially close
. the breaker until the pin lines up with two holes in
the sides of the mechanism frame Hold the moving
.3 Check the above adjustments on all three
. poles After all poles have been adjusted and with
one set of arcing tips just touching, the clearance
. between the other two sets of arcing contacts should
not exceed */te inch
. core up, and then drive the pin to the right just
far enough to clear the moving core rod Lower the
. moving core until it hits its stop. Drive the pin to
the left into its original position
. . 5 Remove the four mounting bolts
-- ·The first letter or number refers to the item and the second to the figure number. (Item J Fig. No. 3.)
14
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INSTALLATION
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"DB" AIR CIRCUIT BREAKERS
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. FIG, 4 Adjusting Limits of Main and Arcing Contacts
a. Cautions These bolts are also the
- mounting bolts for the closing solenoid ;
therefore, support the solenoid while remov ing the bolts.
.6 Remove the mechanism. .7 Before assembling mechanism check sliding
. surfaces of two latches shown at UB", Fig 3, These
. . surfaces must be clean, free of burrs, and have not
more than 035 inch clearance in the reset position
The mechanism is factory lubricated for life.
CLOSING SOLENOID
. - . The closing solenoid (Fig 5) is non adjustable
To remove the close coil, proceed as follows:
1. Caution: Remove the close coil circuit voltage.
. - 2 Disconnect the wires from the close coil ter
. minals
3« Loosen the locking clip (4) on the bottom of the moving core,
7 BREAKER TYPE
CLOSING NOMINAL
COIL BURDE
N
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CONTROL YOLTAGE
CLOSING AMPERES
TRIPPING AMPERES
RECOMMENDED FUSE AMPERE
CLOSING RATING
250 VOLT
Standard
Tima
NEC
Lag
600 VOLT
Standard Tima
NEC
Lag
FUSE STYLE NUMBER
DB-75
All
48 DC
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125 DC 32
250. DC 18
230 AC 32
460 AC 18
575 AC 15
5
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120A823H04 120A823H03
12OA023HO4 120A824H03 120A824H03
-DB-100
DBF 40
All
24 DC
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125 DC 32
250 DC 18
230 AC 32
460 AC 18
575 AC 15
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120A823H05
120A823H04
120A823H05 120A824H04 120A824H04
115 AC
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- Note: For A C closing use 3 KVA source or larger
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MAINTENANCE,
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. . FIG 5 Closing Solenoid Construction Details
.4 Remove bolts (5), locking clip (4), and the
The various ratings of each general type are of
ry
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relay trip bracket (6),
.5 Remove bolts (3), and using a rawhide or
. plastic mallet remove the bottom stationary core (7)
. . 6 Remove the coil
.7 After assembling coil and breaker, but before
similar construction and differ only in springs and
calibration, The overcurrent tripping device can be removed
from the breaker easily and replaced with another
. unit of the same or different rating without affecting
the calibration of the units involved
i
connecting the coil, ch$?k proper co-ordination
. - between breaker closing ahd relay tripping Ener - gize relay operating coil only (Fig, 11), and manual
. ly close breaker very slowly The relay contacts
- should trip free slightly before the position at which
the mechanism pawl (C 3) drops in the latched
position.
- Construction. The mounting frame casting sup - . ports the two sub assemblies of the trip unit On the
upper part of the frame are the two magnetic armatures and their associated links and brackets* Fastened to the lower part of the mounting frame is
. the moldarta box which contains the calibration
springs, time delay elements and calibration knobs
OVERCURRENT TRIPPING DEVICE
. This box is held to the mounting frame by two long
screws at the bottom of the calibration box
. Description The overcurrent tripping device Installation and Removal
·.' I
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. (Fig 6), for the circuit breaker is an air delayed
- - magnetic type of device. The time current character
. . istics of the trip unit are as follows: 1 Long delay and short delay . 2. Long delay and instantaneous . . 3 Instantaneous
Caution: Before removing or installing a
- . tripping device, be sure that the breaker is in
the open position and de energized
To remove an overcurrent tripping device from
- . the breaker, loosen the two bolts at the bottom
of the mounting frame (L 3) until they turn freely
18
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MAINTENANCE
Then loosen the two bolts at the top of the mounting
. frame while supporting the trip unit so that it
does not fall These two bolts clamp a slotted angle mounting bracket and merely have to be loosened;
. they do not have to be removed from the mounting
frame The trip unit is then free to be removed
. from the breaker by lowering it down behind the
breaker platform
To install a tripping device on a breaker, first
make certain that the breaker is open and is not connected to live circuits, Then loosen the upper mounting bolts on the trip unit so that the bolts
. can slide into the slotted mounting brackets on the
stationary yoke Then install the trip unit from the
bottom of the breaker, sliding it up behind the
. mechanism platform Start the bottom two mounting . bolts, but do not tighten completely Next, align the
trip unit so that the gaps between the tapered portions of the main armature are approximately
. equal when the main armature is closed Then
. tighten all four mounting bolts securely
- - KB* 33 850 4 & 5P
"DB" AIR CIRCUIT BREAKERS
. Adjustment of Trip Screw The trip screw
mounted on the trip finger must be adjusted properly
to obtain proper tripping.
Cautions Since this adjustment involves tripping the breaker, care must be taken to
. keep fingers and face away from all contact
arms and operating linkage
- To proceed with the adjustment, turn the long
time dial at the bottom of the calibration box counter
. clockwise to the stop so that the trip unit is set for
minimum time delay Then close the breaker and carefully reach under the mechanism with both
. hands and push the lower armature fully closed
with the thumbs Hold it closed for at least the
minimum long delay time (20 to 40 seconds). If the
breaker trips, reset the screw at the end of the
. tripping finger until the breaker just barely trips
Before re adjusting the trip screw, make sure that
- . the breaker is in the open position After finding
the position of the trip screw at which the breaker
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. . - FIG 6 Cross Sectional View of Overcurrent Tripping Device with Long Delay and Instantaneous Elements
19
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. just trips, turn the screw exactly one full turn in
the direction to trip the breaker sooner Check to make sure that the breaker will trip when either armature is closed if long and instantaneous type trip units are used, or when both armatures are closed if long and short delay type trip units are
. . used The short delay armature is for timing only
. Closing it alone will, not trip the breaker
Operation
. Standard Overourrent Tripping Device
(Ke£er to Fig 7A) When a small overload current flows through the
breaker pole unit conductor (R), it causes the moving
. armature (B) to be attracted toward the stationary
core (A) The motion of the armature is retarded by the diaphragm (D) whose motion is in turn controlled by the amount of air admitted by the long time delay
valve (F), After a time delay, determined by the setting of valve (F), the armature will have rotated
. the trip crank (J) far enough to trip the breaker by
moving the trip lever (K) During this type of tripping, the tension spring (C) is not stressed
. beyond its normal length
- On larger overload currents, the action is essen
tially the same as above except that the moving
. armature (B) will close completely as soon as the
overload is applied When the armature closes, the
LEGEND*
A'LONG DELAY STATIONARY MAGNET
-8 LONG DELAY MOVING MAGNET
-C LONG DELAY FORCE LIMITING SPRING -D DIAPHRAGM -E AIR CHAMBER
-F LONG DELAY VALVE AND DIAL
- - G LONG OELAY PICK UP CALIBRATION SPRING
-H RESET VALVE
-J TRIP CRANK -K BREAKER TRIP FINGER -L INSTANTANEOUS STATIONARY MAGNET
-M INSTANTANEOUS MOVING MAGNET - - Q INSTANTANEOUS PICK UP CALIBRATION SPRING -R BREAKER MOVING CONTACT ARM -W SHAFT
GUIDE BEARING
1 SOLID JOINT
+ PINNED JOINT
- -j NO JOINT
1 STOP SURFACE
RESETTABLE DELAY
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SCHEMATIC DIAGRAM
CURRENT MAGNITUDE
FIGURE 7 A
TYPICAL TRIPPING CHARACTERISTICS
FIGURE 78
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. . - FIG 7 Schematic and Typical Time Current Characteristics of Overcurrent Tripping Device with Long Delay and Instantaneous Elements
20
Courtesy of store.ips.us
MAINTENANCE
tension spring (C) applies a force to diaphragm (D), After a time delay determined by valve (F), the diaphragm movement permits the spring to rotate
. the trip crank (J) far enough to trip the breaker by
moving the trip lever (K) Large fault currents cause the instantaneous
. armature (M) to close immediately This armature
. Ufts the trip crank (J) without any delaying action
and trips the breaker
Selective Overcurrent Tripping Device (Refer to Figs. 8 to 9)
- For small and intermediate overloads, the opera
tion of this device is the same as for the standard
overcurrent tripping device. However, the selective
. overcurrent tripping device operates differently
when large fault currents occur When the fault current is large enough to close
. - - LB 33 850 4 & 5D
"DB" AIR CIRCUIT BREAKERS
the short delay armature (M), the linkage attached
to the armature opens valve (P) which permits air
. to enter the diaphragm chamber at a much faster
rate than through the long delay valve (F) Tripping
. is then accomplished by the same means as though
a small overload had occurred That is; the main
armature (B) has closed, pulling on the tension
spring (C) which is restrained by diaphragm (D) until sufficient air has entered valve (P) to permit
. the spring assembly (C) to lift crank (J) and trip the
breaker by rotating the trip finger (K)
- A discriminator arm is used on the selective over
current trip units to make the unit behave as an instantaneous type trip unit while the breaker is being closed and for a short interval of time after
. closing This is achieved by having a discriminator
latch connection between the short delay armature
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. . - FIG 8 Cross Sectional View of Overourrent Tripping Device with Long Delay and Short Delay Elements
21
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MAINTENANCE,
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Parts which Discriminate between:
.A Breaker in Closed Position
.B Breaker During Period of Closing . FIG, 8A
FIG b Arranged for Long
Delay and Short
Delay Tripping
Selective Overcurrent Trip Operations
. FIG c.
- Arranged for Long
Delay and Instan taneous Tripping
S
. bracket and the trip crank When this latch is
The long delay pick-up adjustment can change
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. - engaged, the short delay armature will lift the trip the position of the upper part of the curve through
crank directly if the current is greater than the the range indicated by the number (1) This adjust
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- short delay pick up setting, If the current does not
rise above this value, tfyen the breaker remains
closed and the discriminator arm disengages the
ment is accomplished by changing the tension on
. the spring which controls the force the long delay
armature must overcome in order to close
discriminator latch so that the trip unit will then
. revert to its normal function as one having long
and short time delay characteristics
Instantaneous Overcyn'ent Tripping Device
(Single Element) Refer to Fig. 10
This device operates in an instantaneous manner
- to trip the breaker at any time when the current
rises above the calibrated setting. The main arma
. ture (B) of Fig 7A, is modified so that it lifts the
. - crank (J) and trips the breaker directly The opera
- tion is similar to the instantaneous trip of the stand
ard overcurrent tripping device,
- Time Current Characteristics
Standard Overcurrent Tripping Device
. (Refer to Fig 7B)
The long delay time adjustment can be used to
. shift the knee of the curve over the range indicated
by the Number (4) This adjustment is changed by
turning the knob, located at the bottom of the molded calibration box, which opens or closes the valve to
control the amount of air entering the diaphragm
chamber.
The instantaneous pick-up adjustment can shift
the vertical part of the curve to the left or right as
. - indicated by number (2) This is achieved by chang
- ing the spring force applied to the smaller instan
. taneous armature
- The flat portion of the curve at the bottom repre
sents the minimum time for the breaker to clear
. when fault currents exceed ten times the trip unit
rating
22
Courtesy of store.ips.us
MAINTENANCE,
LEGEND*
-A LONG DELAY STATIONARY MAGNET
B-LONG DELAY MOVING MAGNET
C-LONG DELAY FORCE LIMITING SPRING 0`DIAPHRAGM
-E AiR CHAMBER -F LONG DELAY VALVE ANO DIAL - G'LONG DELAY PICK UP CALIBRATION SPRING
-H RESET VALVE
J-TR1P CRANK
-K 0REAKER TRIP FINGER
L- SHORT DELAY STATIONARY MAGNET
. - - .I B 33 850 4 & 5D
"DB" AIR CIRCUIT BREAKERS
M-SHORT DELAY MOVING MAGNET
-N SHORT DELAY OVER TRAVEL SPRING
- P-SHORT DELAY VALVE
Q-SHORT DELAY PICK UP CALIBRATION SPRING
-R BREAKER MOVING CONTACT ARM
S-OISCRIMINATOR ROLLER
-T OtSCRIMINATOR TIME DELAY PISTON
U-DISCRIMINATOR LEVER
V-DISCRIMINATOR LATCH
W-SHAFT
t GUIDE BEARING
SOLID JOINT
4- PINNED JOINT ---j NO JOINT
1 STOP SURFACE
LONG DELAY PICK-UP ADJUSTMENT
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-TOTAL CLEARING TIME
LONG OELAY TIME ADJUSTMENT
RESETTA8LE DELAY
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SHORT DELAY TIME ADJUSTMENT
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CURRENT MAGNITUDE
TYPICAL TRIPPING CHARACTERISTICS
FIGURE 9A
<J{ v- FIGURE 98
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FIG 9 Schematic and Typical Time Current Characteristics of Overcurrent Tripping Device with Long Delay and Short Delay Elements
. Selective Overcurrent Tripping Device
(Refer to Fig 9B)
- The time current characteristic of this trip unit
is the same as the standard device except that the
. - position of the flat portion of the curve can be
shifted as indicated by the number (3) This adjust
. - ment can be made by changing the setting of the
short delay time on the calibration box The adjust ment controls the maximum opening of the short delay valve and thereby controls the tripping time
. when currents are high enough to operate the short
delay armature
Calibration. Overcurrent tripping devices of
this general type must be calibrated by using a
- definite procedure and technique, as well as spe
. cialized equipment Because few customers have
access to such equipment, it is highly recommended
. that trip units be returned to the factory if it appears
that they need to be calibrated
Maintenance. In ordinary use, this trip unit
. needs very little maintenance. Any accumulation of
dust should be blown off occasionally No oil or
. lubricant should be applied to any of the pins or
links Do not disassemble the unit for cleaning
purposes. In the event that major repair work is
needed, it is advisable to return the unit to the
. factory
23
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MAINTENANCE
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CONTROL RELAY
. The control relay (Fig 11) mounts directly under
. - the auxiliary switch It is a single coil, mechanical
tripping device with the coil suitable for continuous
. duty The operation sequence is outlined in Fig. 2, . Page 13 The contacts should normally last the life . of the breaker, but are replaceable if necessary
The relay trip pin and relay toggle release are
. intermittent duty only, The shunt trip circuit must
always be opened by an auxiliary switch contact
- Inspection. With the breaker in the open posi
tion, manually push the shunt trip moving core
against the stationary core and manually attempt to
. . close the breaker The breaker should be trip free
- The trip rod of the shunt trip should have approxi
. mately %2 inch clearance to the trip rod clip
designed so that the relay trips at approximately the
. same time as the breaker latches The relay is not
. adjustable
.Maintenance. Check for loose bolts and faulty
coil
. Inspection Make certain all circuits are de
-- energized, Manually close the breaker until the re
lay toggle release raises the lift link to engage the
. relay release lever; this should occur just before the
end of the moving core travel Slowly open the
. breaker and make sure the lift link and relay toggle
release return freely to their normal positions
*i5
. Maintenance Remove screw in front cover
. plate Remove cover by grasping it at the bottom
. and pull down and out Check for loose screws, . especially at contacts Replace cover and check . for loose mounting bolts
Ir
. SHUNT TRIP ATTACHMENT
The shunt trip (Fig 12) mounts on top of the
!:
. - platform immediately to the right of the operating
mechanism It is non adjustable and is intended for
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. . - FIG 10B Typical Time Current Characteristics of Overourrent Tripping Device with Instantaneous Element Only
UNDERVOLTAGE TRIP ATTACHMENT
- The undervoltage trip mounts on top of the plat . . . form, to the right of the shunt trip (See Fig 13)
Its function is to trip the breaker when the voltage
falls to between 30 to 60 percent of normal, Turn
.the reset lever screw to secure approximately 14
oz push out force on the moving core when the
latch releases.
The moving core is normally held magnetically
against the stationary core to hold the Micarta rod
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. . FIG 10A Schematic Diagram of Overourrent Tripping Device with Instantaneous Element Only
- and consequently the reset lever, in the reset posi
. tion When the coil voltage is reduced sufficiently,
- the reset lever spring overcomes the magnetic at
24
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"DB" AIR CIRCUIT BREAKERS
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. traction of the cores and rotates the reset lever
clockwise As the reset lever rotates, it carries with
it the latch pin
. until the latch is
which rotates relative to released When the latch
the latch
releases,
- the trip spring rotates the trip lever counterclock
. wise to trip the breaker The linkage is reset by the
. . cross bar as the breaker opens Fig 13 shows the
. cross bar in the open position of the breaker
- The self locking screw in the moving core is set
. at the factory and should not require adjustment
It is used to secure latch release when the moving
slowly, allowing the undervoltage trip spring to
. rotate the trip rod and trip the breaker after a time
delay
. . . Caution: Do not use your fingers to hold
and release the U V reset lever
. Maintenance Check for loose bolts and faulty
. coils AUXILIARY SWITCH . The auxiliary switch (Fig IS) mounts on top of
. the platform to the left of the operating mechanism
. core is %2 outside the frame, (Change to Vie" when
a time delay is used) Always connect the coil to the line side of the
The contacts will carry IS amperes continuously or
. 250 amperes for 3 seconds
- - The switch is a shaft operated, 4 pole, rotary type
. breaker unless the attachment is equipped with a normally having two "a" contacts (closed when the
time delay device In this case, the time delay will breaker is closed) and two "b" contacts (closed
delay the tripping of the breaker long enough to permit energization of the undervoltage coil from
. the load side Do not use an auxiliary switch contact
. in the undervoltage circuit
- - . when the breaker is open). The rotor operates
through a 90 degree angle and is non adjustable
. However, the contacts may be changed from "a"
to "b" or vice versa To change, remove the switch
The trip lever of the undervoltage should have
. approximately Vie inch clearance to the trip bar
when the breaker is half way closed .
from the platform, remove the back cover, shaft and
. end bushing Remove the rotor and change the . contacts as desired Be sure to replace the shaft in
UNDERVOLTAGE TIME DELAY
Table No. 3. INTERRUPTING CAPACITY
ATTACHMENT
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The undervoltage air dashpot time delay attach*
. - ment (Fig 14) mounts on the front of the under
. voltage trip, replacing the moving core cover The
VOLTS
INTERRUPTING CAPACITY IN AMPS.
-NON INDUCTIVE CIRCUIT
INDUCTIVE CIRCUIT
needle valve screw in the top regulates the opening
. through which the air is forced and hence the time
delay The attachment does not have a quick reset feature and therefore approximately one minute
125 V. D-C
- 250 V. D-C
115 V. A C
450 V. A-C
11 2 75 25
6.25 1.78 15 5
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. . should be allowed between operations to permit
complete resetting It is set to trip in 4 to 7 seconds
. Inspection. Hold th U V, trip lever down and
^^ . close the breaker manua y Release the trip lever
. the original position relative to one of the unchanged
contacts
Inspection. Remove the front cover and make
. sure contacts are touching well before the end of
travel
. Maintenance. Check for loose bolts. Replace
contacts if necessary
ALARM SWITCH ATTACHMENT
. The alarm switch (Fig 16) is integrated with the
shunt trip attachment and will energize the alarm
circuit on all opening operations except those
initiated through the push to trip button and shunt
. trip The alarm switch may be reset manually by
-. trip button or electrically by energizing the shunt
trip coil (when electrical resetting has been pro
vided). Closing the breaker also resets alarm switch Inspection. Close the breaker manually and
t
-- FIG. 12. Shunt Trip Attachment Construction Details then trip by trip button to be sure the alarm contact
26
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MAINTENANCE
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. . -- FIG 14 Undervoltage Time Attachment Construction Details
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. -- FIG 15, Auxiliary Switch Construction Details
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"DB" AIR CIRCUIT BREAKERS
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RESET LINK
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. -- FIG, 16 Alarm Switch Attachment Construction Details
. do not "make" Repeat the above procedure except . . . . trip by raising the O C T trip finger Note that the
. alarm contacts do make contact
. Maintenance. Clean the alarm contacts when
necessary Check for loose bolts.
ELECTRIC LOCKOUT ATTACHMENT
. The electric lockout (Fig 17) mounts on the top . of the platform, on the extreme left side Its function
- -- . is to hold the breaker open (trip free) until the lock
out coil is energized The lockout coil can be de en
- ergized after closure of the breaker, if desired, with
. out tripping the breaker
. Inspection. Attempt to close the breaker The
present lockout should
closure of the breaker by
. holding the trip rod in the trip free position Hold
ing the lockout armature in the closed position
. should permit closure of the breaker Releasing the
. armature after closure should not trip the breaker
. - . Maintenance. The device is non adjustable
Check for faulty coil and loose bolts
KEY LOCK ATTACHMENT (For Fixed Breakers)
. The key lock (Fig 18) mounts on the right side
. of the operating mechanism frame The key can be
removed in the open or closed position of the
breaker.
Inspection. Push the trip button and turn key
. to the locked position The key is then removable
- . and the breaker is locked in the trip free position
Replace key and rotate to the unlocked position to
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. -- FIG, 17 Electrical Lockout Attachment Construction Details
29
Courtesy of store.ips.us
MAINTENANCE
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. . -- FIG 18 Key Look or Key Interlock Attachment For Fixed Breakers Construction Details
. free breaker trip button The key is also removed in
this position,
- . . Maintenance The device is non adjustable . Check for loose bolts only
. . Inspection There are no moving parts Make
- certain a c incoming leads are connected to proper
. terminals . Maintenance. Check for loose connections
KEY INTERLOCK ATTACHMENT
REVERSE CURRENT TRIP ATTACHMENT
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(For Fixed Breakers)
. The key interlock (Fig, 18) mounts on the right
side of the operating mechanism frame When
. the key interlock attachment is furnished, the key
lock attachment cannot be supplied With the key
- . To protect direct current equipment from reverse
currents, a reverse current trip attachment (Fig 20) is installed in place of the center pole unit, making
- . a two pole breaker This is a magnetic device
. influenced by two circuits The first is the potential
. interlock attachment the key cannot be removed
unless the breaker is locked in the open position
. Inspection Push the trip button and turn key
coil which magnetizes the armature and the second
. is the main current which magnetizes the frame
- When current flows in the forward direction, arma . ture movement is prevented by a stop When the
- . . to the locked position, TJie key is then removable current reverses the armature rotates in the opposite
and the breaker is locked' .in the trip free position direction and trips the breaker
Replace the key and rotate to the unlocked position
. to free the breaker trip button The key is not
. removable in this position
. After tripping the reverse current, armature is
reset by opening the potential coil circuit For this
- . Maintenance. The device is non adjustable.
reason the coil is always connected through an "a"
contact of the auxiliary switch
. Check for loose bolts and nuts only
- RECTIFIER UNIT FOR A C
ELECTRIC LOCKOUT ATTACHMENT
- - When an a o electric lockout attachment is re
quired, a RECTOX unit is mounted underneath the
. - breaker platform under the undervoltage device as
shown in Fig. 19 An auto transformer is provided in
Calibration adjustment covers 5 and 2S per cent
. reverse current, based on normal current rating - Space is provided under the attachment for mount
. ing switches for indicating lights or alarm devices
. Inspection. Close the breaker manually Reach - under platform and slowly move the armature to
. ward the pole piece to trip the breaker Armature
V;
the unit so that the common voltages, for 60 cycles
. and 25 cycles can be connected to the appropriate
terminal on the unit A terminal block is mounted
on the rectifier unit to facilitate all wiring.
should move without friction and should have
approximately VSa inch overtravel after tripping.
. Adjustment can be made by turning trip screw
- With breaker in open position move armature to
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. . - FIO 19 Rectifier Unit for A C Electrical Lookout Attachments
. . - ward
- . from
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be heard
stop posi
. . tion. Adjustment can be made at lower trip screw
Maintenance Check for loose bolts of attach ment as well as bolting of associated connectors Check potential coil for open circuits and to ground
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. FIG 20 Reverse Current Trip Attachment Types "DB 75" and "DB 100" Air Circuit Breakers
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riELD DISCHARGE SWITCH
- - - The DBF 40 breaker is a two pole DB 100 breaker
- having special arc chutes and modified arcing con . . tacts plus a field discharge switch mounted on the
center pole (Fig 21) The field discharge switch is normally shipped
- with an overlap of approximately 1/32" between
the side pole contacts and the field discharge con
. - 1.8 33*850 4 & 5D
°OBM AIR CIRCUIT BREAKERS
tact by following the adjustment steps shown in the
. figure
Inspection. Remove the arc chutes, close the
breaker manually to check for freedom of motion and to see that the field discharge adjustment is
. within i/a" open gap to i/s" overlap relative to the
side poles
Maintenance. Clean the contacts if necessary,
. check contact relationship and adjust if necessary
. Check for loose bolts
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. . - FIO 21 Cross Section View of Field Discharge Pole Unit
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- - Recommended Spare Parts for DB 75 and DR 100 Air Breakers
. . NAME OF PART
(ALWAYS GIVE BREAKER S 0 NUMBER)
STYLE NUMBER
OR PREFERENCE
NUMBER PER
BREAKER OF DEVICE
NUMBER RECOMMENDED
For Breakers
1
2 to 5
6 up
AUXILIARY SWITCH
4 Pole Switch Unit
... Front Cover
. Contact Finger . . Contact Segment
184 185
. CONTROL RELAY Operating Coil -- .. Blowout Coil and Circuit L P, -- Blowout Coil and Circuit R P, Moving Contact . Stationary Contact Cover
--.. POLE UNIT Stationary Arcing Contact
..
Stationary Main Contact Top
-- . Stationary Main Contact . Bottom » « » ^ ·
. Moving Arcing Contact
Moving Main Contact .
ELECTRIC OPERATION Closing Coil
Shunt Tripping Coil
Overcurrent Device Complete
-- . RETAINING RINGS ASSORTMENT DB 75 -DB 100
.Fig 15
.No. 187
No 186 1397 624
1397 641
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153 160 159
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Fig 12 No 300
.Fig 6
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15 DB100
--12 DB75 -18 DB100
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MEMORANDUM
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FROM UESTINGHOUSE ENG SWC
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TO 13106950995
P , 001 '
. PAGE 001/001
F:T*N
DS and DSL Low Voltage Power Circuit Breakers
. DS wd DSl low vcrtuw IWWMW bn k f« are
· . * * . auopilfK} With sartd au.ta iripelno davlw
providing adjustable overcurrem tripping
* function* such as long 0t «y, short delay
andinatanwn«oua eharaeforlstto aim
. irloplne tuade IncrtoMlnn and can fflatura
miagraf adfuata&fe ground fault profectfon
iM-
-r . * \ **
Ordering (n 0 n 1fo
* " * * . Wb«n ordering rircuft breaker epaeffy
* * Karo
Type
Choice of Specification
..
p$/D$i-afifr oftapei-h Dsao6E> &s/p3i»4io, PS-IISH, 05*430, DS/DSL-CTZ, Ds/PSL-yo
Mounting
Operadon
Fixed of removable (drawout) Manual or electric stored energy tf rtiictrlGt ), apeoWV cantral voh&Q4, ds or ac and frequency
Circuit or Service Samar bating
Raring Plug
* * * Voltes ISO w 60 hertzf,600 volt * imau
Sea page 3
- For Pieftrip RMS breakers apgclfy sensor recing and rating plug alga from Table 3 of SIB aa »7QQ>1G
Type of Trip
A» Tripping function
* U Long delay andinstantaneous , U6 Lonfi delay inaunwtfwus end ground fault
LS Long delay and short delay
** * LSI
LSG LSIG
Lang
Long Long
dddaeetlloaaYyy,,i s$hh0oornt
Way and instantaneous Way and groundfeolt delay,Instantaneous and
ground
fault
a. 3 or 4 wire ground fault pictocrioft, If required
Enclo$iufa
Erector set program
- Subatructure
One high drawout celt
Power module
Whan ordering optional attachment!r specify:
item
Crtolce of Specification
Shunt Trip Attachment Specify oonwal voltage, do or «c and frequency
(Manually Operated
Breaker!
UndorvoUage Trip Non*Arfjusiabfe
OverCurrent Trip Switch
EtaotriM Lookout
- > Insaantanaous
.
ortime
delay,
specify
k
control
voltage,
dc
or
ac
and
frequency
U
» ^ < IMf a|nuatrlllcyacllryerleescetrt,icsaplleycriefysceot*nstproecl vifoylntaugmebdecr
of or
contacts ac and frequency
41
Spstfjjjy control voltage, dc or ac and frequency
{Manually Operated
T
+ 9t &kAt$)
Electric Close Release Specify control voltage, dc or ac end frequency
(Manually Operated
Breakers) UL Usled Label
. See Modtfication Tattle.UL Labels are available lor all DS breaker elements and fuse trucks
Stamford Ratings of Typa 0$ Low Voltage Air Clroih Breaker?
Broker Type DS
L$ 208
209H 206B 416
« 41 H
420
632
940
Continuous Current Amperes
600 800
800 1600 1600 2000
5200 4000
Tortiparature Rise, *C- Max.
600V 80 Hx Fully Rated Breaker 600V 69 Hz Selective Breaker
- * * J&V 00 Hz Fufly Rat d Breaker 400V 60 Wj Selective Breaker 240V 60,H2 Fully Bated Breaker 340V 60 Hi Selective 8maker
(Ajrt(jy Syml A>"1
iAmpfiSym)
65
95
30.000 42.000
30.000 42,000
(Amps Sym)
* (Amp Syml 4W»
^ (Amps Syml &
lAmpsSyml
30,000
30.000
42,000 30.000
42,000 42,000
50,000 42.090
as
65
50,000 42,000 42,000 42,000
. 60,000 fiO COC
42,000 50,000
65,000 66,000 69.000 50,000
6ft
60,000 00,000
66,000 66,000 66,000 65,000
88
.fsioo.focaaoo
5$,000
65,000
65.000 66,000
86
OS
06,000 85.000
66,000 05,000 .
6855,*000000 «835,,000000
. 65,000 13O 000
65,000 85,000
Courtesy of store.ips.us
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-17'
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(MON
)
10: 25
P, 002
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Go.
TYPEDS LOW VOLTAGE POWER CIRCUIT BREAKERS
Breaker Type
Ratings and Characteristics
- - DS-2Q6 0S 2O6S IW 4M DSA16S
D&420
DS-632 08^840
Voltage Rating (AC only)
600
600
600
600
600
600
600
Frame She(Max, Continuous Amp) 800
800
1600
1600 3000 3200 4000
- Interrupting Ratings, RMS Symm Amperes at System Voltages:
A. With
Instantaneous
Trip
-Q 24QY
241480V
-481 600V
42,000
30,000 22,000
50,000 65,000 42,000 50,000
42,000 ., 42,000
65,000 · 65,000
50,000
65,000 85,000 130,000 65,000 65,000 85,000 50,000 65,000 85,000
.B With Short Delay Trip
-0 240V
241480V
481-60QV
30,000 30,000 22,000
42,000
42,000 42,000
50,000 50,000
42,000
65,000 65,000
50,000
65,000 65,000 50,000
65,000
65,000 65,000
85,000 85,000
85 ,000
- Operating Characteristics Same for AB Types
/
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Control Voltage
24 DC
48 DC 125 DC
250 DC
115 AC
230 AC
. Close Current (SR), Amp
(1)
NA
5.0
2.0
(2)
L.O
3.0
1-5
. Shunt Trip Currant, Amp.
Spring Charge Motor, Amp (3)
6.0
NA
5S>
7.5
2.0 3.0
1.0
t -5
2.0 3.0
1.0 1.5
Close Voltage Range Trip Voltage Range
-14 30
-40-50
28 60
-90 130
-70 140
-180 260
-14 280
-95-125
95 125
190 250
--190 250
^^ (1) Not rcoommended voltage,
. (2) Chec WastlngJiause for application at this control voltage . (3) Running current:Inrush, approximately 400%
Spring Charge Time - 5 seconds maximum
- Time for Spring to Close Breaker, until contacts touch 4,5 cycles maximum
- Opening Time with Shunt Trip 3 cycles maximum
- Interrupting Time, at 200% or more of Inst. Pickup 3 cycles maximum (4)
. - Interrupting Time, 100% to 200% af Inst Pickup 4 cycles maximum (4)
Arcing Time, Below 50% of Continuous Rating ·6 cycles traxfmum (4)
(4) Add approximately 2 cycles per shunt trip and approximately 4 cycles for Instantaneous undervoltage.
/
-. v'i J '
. MB 3282A VOL 11
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-- - Courtesy of storAe' :.iAp. s.u.s... I'hi'< '7; ..Vr ;)U*:,
Aspose.Pdf for .NET 9.7.0 Aspose Ltd.